The association between metabolic control and prevalent macrovascular disease in Type 2 diabetes: the VA Cooperative Study in diabetes

Abstract

The problem: Macrovascular disease (MVD), especially coronary heart disease, is the most common cause of mortality in Type 2 diabetes. We assessed the association between demographic and clinical variables (particularly HbA1c) and prevalent MVD at time of enrollment into the VA Diabetes Trial (VADT), a 7-year randomized trial to determine whether intensive glycemic control will reduce risk of MVD events in older participants with established Type 2 diabetes.

Research design and methods: We compared the demographic, treatment, and clinical characteristics of participants with and without known MVD, then assessed the interaction of multiple variables with HbA1c. Logistic regression models evaluated the association between HbA1c quartiles and prevalence of MVD, adjusting for potentially confounding variables.

Results: Several variables were associated with prevalent MVD (age, duration of diabetes, insulin use but not daily dosage, smoking history, hypertension, BMI, Caucasian race, non-Hispanic ethnicity, lower HDL cholesterol, higher triglycerides, lower LDL cholesterol, and statin use). In univariate analysis, there was no association of HbA1c with MVD (mean: 9.4+/-1.46% in those with MVD, 9.5+/-1.58% in those without). Multivariate analyses found little confounding of the lack of association of HbA1c with MVD. Only adjustment for age produced a slight increase in the odds ratio, but only for the highest quartile of HbA1c.

Conclusions: In this cross-sectional analysis, MVD was associated with a number of clinical and demographic variables but not with HbA1c. Determining whether intensive lowering of HbA1c will reduce the prospective rate of MVD events in this population of older participants with established Type 2 diabetes is the primary objective of our trial.